“The movie takes some twists and turns, but as a guy, I think he’s crazy,” Jake Johnson said of the film’s protagonist, Kenneth, played by a delightfully delusional Mark Duplass. “The character is written in a really great way,” added Aubrey Plaza. “Kenneth is kind of always surprising you. You don't know if he’s crazy or if he really knows what he’s talking about or what’s going on with him. And I thought that really came through in the script, but it really came through with Mark Duplass’ performance.”

“I felt like he really brought a vulnerability to Kenneth that makes him so likeable and that makes the conflict that much richer,” continued Plaza.

The film follows Johnson, Plaza and Karan Soni’s characters as they seek out the man behind a bizarre and ominous newspaper ad, calling for a partner to go back in time with, for a magazine story. “Wanted: Someone to go back in time with me. This is not a joke. You’ll get paid after we get back. Must bring your own weapons. Safety not guaranteed. I have only done this once before,” the ad reads.

Among the story’s conflicts is the involvement of Plaza’s character Darius with Duplass’ Kenneth. While Darius attempts to create a relationship with Kenneth, she struggles to come to grips with the romantic feelings she has also developed.

“I felt like she wasn’t a character that you could put in a box and label any which way,” Plaza said.

The Derek Connolly-penned script was first brought to Duplass as a producer, with Plaza and Johnson attached to act. At the time, before the explosion of NBC’s Parks & Recreation and Fox’s New Girl, the duo were relatively unknown actors.

“I just really loved the script,” explained Duplass. “It treated the characters with so much respect. They’re quirky, but you can tell that the filmmakers really love these characters in the film. So I was just really excited to do something that was in my wheelhouse.”

Filmmakers opted to keep the actors in the dark about how the story would end, shooting multiple finale scenes before calling a wrap. So when the film made it’s world premiere at the Sundance Film Festival, Plaza and Johnson were as surprised as the rest of the audience during the final scene.

“It was really fun to watch it with an audience,” said Johnson. “Their reaction to it alone kind of trumped anything I would think. People love it. Watching people celebrate that ending was a pretty cool experience.”

For more from THR’s interview with the trio, watch the video above. Below, the actors get real in THR’s “Sh*t Talking With Aubrey Plaza, Jake Johnson and Mark Duplass,” in which the group exchanged lighthearted barbs at each other’s expense.

Among the highlights? “Jake is just like, a violent monster that I dodged the entire time,” zinged Plaza, while Johnson counterd: “As an actor, as a fellow peer, she’s the worst. It’s like acting with a dead animal.”

“Those are my two red-headed stepchildren and I'm the dad,” joked Duplass of his role as on-set mediator.